In this study, the electrochemical behavior of Sm on the binary liquid Al-Ga cathode in the LiCl-KCl molten salt system is investigated. First, the co-reduction process of Sm(III)-Al(III), Sm(III)-Ga(III), and Sm(III)-Ga(III)-Al(III) on the W electrode (inert) were studied using cyclic voltammetry (CV), square-wave voltammetry (SWV) and open circuit potential (OCP) methods, respectively. It was identified that Sm(III) can be co-reduced with Al(III) or Ga(III) to form AlzSmy or GaxSmy intermetallic compounds. Subsequently, the under-potential deposition of Sm(III) at the Al, Ga, and Al-Ga active cathode was performed to confirm the formation of Sm-based intermetallic compounds. The X-ray diffraction (XRD) and scanning electron microscopy-energy dispersive spectroscopy (SEM-EDS) analyses indicated that Ga3Sm and Ga6Sm intermetallic compounds were formed on the Mo grid electrode (inert) during the potentiostatic electrolysis in LiCl-KCl-SmCl3-AlCl3- GaCl3 melt, while only Ga6Sm intermetallic compound was generated on the Al-Ga alloy electrode during the galvanostatic electrolysis in LiCl-KCl-SmCl3 melt. The electrolysis results revealed that the interaction between Sm and Ga was predominant in the Al-Ga alloy electrode, with Al only acting as an additive to lower the melting point.

Li-Cd 합금을 이용한 환원추출방식을 LiCl-KCl 기반의 drawdown 공정에 적용하게 되면, LiCl-KCl 공융염의 조성이 파괴되므로 공정온도를 높여야 하며, 전해정련 및 전해제련과 같은 공정에 LiCl-KCl 용융염을 재사용할 수 없게 된다. 따라서, 본 연구에서는 공융염 조성에 적합한 Li-K-Cd 합금을 제조하였으며, 이를 이용하여 U와 Nd가 포함된 LiCl-KCl 염에 투입하여 용 융염 내 UCl3의 제거가 가능한지 평가하였다.

The microstructural evolution and modulation of mechanical properties were investigated for a Ti65Fe35 hypereutectic alloy by addition of Bi53In47 eutectic alloys. The microstructure of these alloys changed with the additional Bi- In elements from a typical dendrite-eutectic composite to a bimodal eutectic structure with primary dendrite phases. In particular, the primary dendrite phase changed from a TiFe intermetallic compound into a β-Ti solid solution despite their higher Fe content. Compressive tests at room temperature demonstrated that the yield strength slightly decreased but the plasticity evidently increased with an increasing Bi-In content, which led to the formation of a bimodal eutectic structure (β-Ti/TiFe + β- Ti/BiIn containing phase). Furthermore, the (Ti65Fe35)95(Bi53In47)5 alloy exhibited optimized mechanical properties with high strength (1319MPa) and reasonable plasticity (14.2%). The results of this study indicate that the transition of the eutectic structure, the type of primary phases and the supersaturation in the β-Ti phase are crucial factors for controlling the mechanical properties of the ultrafine dendrite-eutectic composites.

Al-based alloys have recently attracted considerable interest as structural materials and light weight materials due to their excellent physical and mechanical properties. For the investigation of the potential of Al-based alloys, a surface porous Al88Cu6Si6 eutectic alloy has been fabricated through a chemical leaching process. The formation and microstructure of the surface porous Al88Cu6Si6 eutectic alloy have been investigated using X-ray diffraction and scanning electron microscopy. The Al88Cu6Si6 eutectic alloy is composed of an α-Al dendrite phase and a single eutectic phase of Al2Cu and α-Al. We intended to remove only the α-Al phase and then the Al2Cu phase would form a porous structure on the surface with open pores. Both acidic and alkaline aqueous chemical solutions were used with various concentrations to modify the influence on the microstructure and the overall chemical reaction was carried out for 24 hr. A homogeneous open porous structure on the surface was revealed via selective chemical leaching with a H2SO4 solution. Only the α-Al phase was successfully leached while the morphology of the Al2Cu phase was maintained. The pore size was in a range of 1~5μm and the dealloying depth was nearly 3μm. However, under an alkaline NaOH, aqueous solution, an inhomogeneous porous structure on the surface was formed with a 5 wt% NaOH solution and the morphology of the Al2Cu phase was not preserved. In addition, the sample that was leached by using a 7 wt% NaOH solution crumbled. Al extracted from the Al2Cu phase as α-Al phase was dealloyed, and increasing concentration of NaOH strongly influenced the morphology of the Al2Cu phase and sample statement.